OBD-II code · Powertrain (manufacturer / generic)
P3409 Cylinder 1 Deactivation Circuit High Voltage
The engine control module has detected high voltage on the cylinder 1 deactivation control circuit. Variant of P3405 reported on platforms with separate diagnostic ranges.
Is it safe to drive with P3409?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyWiring shorted to power
- PossibleSolenoid open circuit
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Cylinder Deactivation Solenoid, Engine Wiring Harness
Related codes
- P3405Cylinder 1 Deactivation Circuit High Voltage
- P3406Cylinder 1 Deactivation Stuck Off
- P3407Cylinder 1 Deactivation Stuck On
- P3408Cylinder 1 Deactivation Circuit Low Voltage
- P340ADeactivation/Intake Valve Control Circuit Bank 1
- P340BDeactivation/Intake Valve Control Circuit Bank 2
- P340CDeactivation/Exhaust Valve Control Circuit Bank 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.